1. Field
A linear compressor is disclosed herein.
2. Background.
In general, compressors may be mechanisms that receive power from power generation devices, such as electric motors or turbines to compress air, refrigerants, or other working gases, thereby increasing a pressure of the working gas. Compressors are being widely used in home appliances or industrial machineries, such as refrigerators and air-conditioners.
Compressors may be largely classified into reciprocating compressors, in which a compression space, into and from which a working gas, such as a refrigerant, is suctioned and discharged, is defined between a piston and a cylinder to compress a refrigerant while the piston is linearly reciprocated within the cylinder; rotary compressors, in which a compression space into and from which a working gas, such as a refrigerant, is suctioned and discharged, is defined between a roller, which is eccentrically rotated, and a cylinder to compress a refrigerant while the roller is eccentrically rotated along an inner wall of the cylinder; and scroll compressors, in which a compression space, into and from which a working gas, such as a refrigerant, is suctioned and discharged, is defined between an orbiting scroll and a fixed scroll to compress the refrigerant while the orbiting scroll is rotated along the fixed scroll. In recent years, among the reciprocating compressors, linear compressors having a simple structure in which a piston is directly connected to a drive motor, which is linearly reciprocated, to improve compression efficiency without mechanical loss due to switching in moving are being actively developed. Generally, such a linear compressor is configured to suction and compress a refrigerant while a piston is linearly reciprocated within a cylinder by a linear motor in a sealed shell, thereby discharging the compressed refrigerant.
The linear motor has a structure in which a permanent magnet is disposed between an inner stator and an outer stator. The permanent magnet may be linearly reciprocated by a mutual electromagnetic force between the permanent magnet and the inner (or outer) stator. Also, as the permanent magnet is operated in a state in which the permanent magnet is connected to the piston, the refrigerant may be suctioned and compressed while the piston is linearly reciprocated within the cylinder and then be discharged. Also, the linear compressor may include a muffler in which a refrigerant passage, through which a refrigerant passes is defined to reduce noise.
A muffler device of a linear compressor according to the related art is disclosed in Korean Patent Publication No. 10-2010-0010421. The linear compressor according to the related art includes a muffler that guides a fluid suctioned into a suction pipe of a back cover to a fluid suction passage of a piston and reduces noise. The muffler includes a muffler main body and a sound absorption tube that protrudes to a center of a front end of the piston.
According to the related art, even though noise reduction effects due to the muffler are expected, the noise reduction effects may be insignificant. Also, there are limitations in reducing noise sources, such as various frequencies (high and low frequencies), that are generated in electrical components, to which the linear compressor is applied, for example, refrigerators or air conditioners.
Also, mufflers according to the related art may be formed of a metal material. When the muffler is formed of a metal material, it may be difficult to mold the muffler, and the assembly process may be complicated. Also, an inside of the piston or cylinder may be under a high temperature environment. Thus, if the muffler is formed of a metal material having a high heat transfer rate, a large amount of heat loss may occur through the muffler.